Pharmacology (Seminar) Flashcards
What is pharmacodynamics?
How the drug affects the body.
What is pharmcokinetics?
What the body does to the drug, involves ADME precesses =
- absorption.
- distribution.
- metabolism.
- excretion.
State 4 mode of actions for drugs (how they achieve their effects)?
1) . Receptors.
2) . Enzymes.
3) . Ion Channels.
4) . Transporters.
What does agonist mean?
Activates the receptor to produce a response.
- substance binds to an receptor which causes an effect.
What does antagonist mean?
Binds to the receptor and blocks the endogenous ligand.
- preventing its effects.
What factors affect the absorption of an oral drug across the GI tract?
1) . How quickly the tablet dissolves.
2) . pH of stomach contents, food, other drugs.
3) . Physiological factors =
- how quickly the drug is moved through the GI tract, e.g. diarrhoea.
What factors affect the distribution of a drug?
- Blood flow to target organs.
- Health of the liver.
- Blood pressure.
- Protein binding.
What happens to the drug in the liver?
1) . Drug is broken down, ready to be excreted by the kidneys.
2) . It gets metabolised by enzymes (becomes inactive).
What is bioavailability?
The proportion of drug which reaches the circulation system.
Will a drug that undergoes extensive first pass metabolism have low or high bioavailability?
LOW
- because it’s been substantially broken down by the liver before it reaches the general circulation.
Digoxin is a drug which undergoes little metabolism and is mainly eliminated through renal excretion. What would happen to the plasma levels of digoxin in a patient with renal impairment?
- Half-life = longer.
- Levels = would increase.
- Increasing risk of digoxin toxicity.
What does it mean if a drug has a narrow therapeutic margin?
Difference between a toxic dose and a sub-therapeutic dose is small.
Name a drug originally sourced from a plant?
- Digoxin.
- Morphine.
- Aspirin.
Name a drug originally sourced from an animal?
Insulin.
Name a drug originally sourced from a mineral?
Calcium carbonate.
Name which drugs aren’t administered orally?
All EXCEPT;
- gentamicin.
- glyceryl trinitrate.
- insulin.
Name a drug that is administered through the nose (inhaled)?
Salbutamol.
Name an orally administered drug which isn’t absorbed from the GI tract?
Lactulose –> inactivated in the liver.
Name an orally administered drug that doesn’t usually cross the blood barrier?
Cetirizine (antihistamine which does not usually cause drowsiness).
Name an orally administered drug that is active when metabolised by the body?
Levodopa (in the brain metabolised to dopamine).
Name a drug which has a narrow therapeutic margin?
- Digoxin.
- Gentamicin.
- Theophyline.
Name a drug that would be completely metabolised (inactivated) by the liver if taken orally?
Glyceryl trinitrate.
Name a drug that is renally excreted and would need extra care in the elderly (lower dose)?
- Digoxin.
- Penicillin.
Name a drug which acts as a receptor agonist?
- Salbutamol.
- Morphine.
Name a drug which acts as an enzyme inhibitor?
- Ibuprofen.
- Aspirin.
- Theophylline.
Name a drug which acts on reuptake transporters?
Citalopram.
